钨钒共溅热致变色薄膜的制备及其红外光学性能

Preparation and Infrared Optical Properties of W-V Co-sputtered Thermochromic Thin Films

摘要:

为解决VO2薄膜相变温度过高，热滞回线温宽过大以及掺杂后红外透过率变低等问题，开展了低成本钨钒共溅热致变色薄膜制备工艺的探索。先在室温条件下采用磁控共溅射的方法于玻璃基片上制备得到含钨量为1.4%的金属薄膜，再在空气中采用后退火工艺使金属薄膜充分氧化为热致变色薄膜。对薄膜样品的物理结构和光学性能进行了分析，发现钨钒共溅没有改变VO2薄膜在玻璃表面择优取向生长，但显著改变了VO2薄膜的表面形貌特征。观察到钨钒共溅热致变色薄膜的相变温度较普通VO2薄膜从68 ℃降低至40 ℃，热滞回线温宽由6 ℃缩小为3 ℃，低温半导体相的红外透过率分别为62%和57%。结果表明，钨钒共溅可达到相变温度降低，热滞回线温宽变窄，掺杂前后红外透过率变化不大之目的。

Abstract:

Tungsten-vanadium (W-V) co-sputtered thermochromic thin films of low-cost were designed in order to solve the problems of pure vanadium dioxide (VO2) thin films including high phase transition temperature, broad width of thermal hysteresis loop and low infrared transmittance after being doped. The metal thin films of 1.4% tungsten concentration were prepared on the glass substrates by magnetron co-sputtering at room temperature, and then the prepared metal thin films were sufficiently oxidized to the thermochromic thin films by annealing under the air condition. The structure and morphology of the samples collected from the prepared thin films were analyzed by XPS, XRD and SEM, which shows that W-V co-sputtering approach does not modify the preferred orientation growth of VO2 thin films on glass substrates, but significantly changes the surface morphologies of VO2 thin films. The optical properties of W-V co-sputtered thin films were compared with that of VO2 thin films by spectrophotometer, and the phase transition temperature drops from 68 oC to 40 oC, the width of thermal hysteresis loop narrows from 6 oC to 3 oC, and the infrared transmittances at low temperature are 62% and 57%, respectively. Results demonstrate W-V co-sputtering approach can reduce the phase transition temperature, limit the thermal hysteresis loop and gently change the infrared transmittance.